Created attachment 57737 [details] [review]
Try alternate protocol on X11 connection failure.
In USE_XTRANS mode, MakeConnection() cycles through a selection of protocol choices until it finds one where it can open a socket to the server. It then attempts an X11 connection via that socket and aborts if one isn't possible.
The attached patch modifies the code to try an alternate protocol if the X11 connection fails.
Tested by starting Xephyr :25 -nolisten unix and xscope -o25 and verified
that before this patch, xscope exited with fatal error when it couldn't
connect to the Unix socket and afterwards it correctly fell back to TCP.
Thanks for the patch - pushed to git master for next release: